National September 11 Memorial and Museum

September 9, 2013

Mary Altaffer/AP

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Contractors work at the National September 11 Memorial and Museum, Friday, Sept. 6, 2013 in New York. Construction is racing ahead inside the museum as the 12th anniversary of the Sept. 11, 2001 attacks draws near. Several more large artifacts have been installed in the cavernous space below the World Trade Center memorial plaza. (AP Photo/Mary Altaffer) ORG XMIT: NYMA103

Mary Altaffer/AP

4of21

Contractors work at the National September 11 Memorial and Museum, Friday, Sept. 6, 2013 in New York. Construction is racing ahead inside the museum as the 12th anniversary of the Sept. 11, 2001 attacks draws near. Several more large artifacts have been installed in the cavernous space below the World Trade Center memorial plaza. (AP Photo/Mary Altaffer) ORG XMIT: NYMA103